Support means for boom ram

ABSTRACT

The invention relates to an improved support means for a boom ram that swings a boom about a horizontal pivot axis on a support. The support means consists of a link pivoted on the support with the cylinder of the ram pivotally carried by the link. The support has first and second spaced stops located in the pivotal path of movement for the link. Releasable lock means are carried by the frame and cooperate with the link to maintain the link in engagement with either of the stops defining first and second positions for the link. In one position, the longitudinal axis of the boom is at all times located rearwardly of a vertical plane extending through the boom pivot, while in the second position, the longitudinal axis is located forwardly of the vertical plane when the ram is fully retracted to define a transport position for the boom.

Redenbarger 51 May 22, 1973 [54] SUPPORT MEANS FOR BOOM RAM [75] Inventor: Philip D. Redenbarger, Centerpoint,

[7 3] Assignee: J. l. Case Company, Racine, Wis.

[22] Filed: Jan. 12, 1972 [21] Appl. No.: 217,341

[52] U.S.Cl. ..2l4/l38 R,214/l32, 2l4/130R [51] Int. Cl. ..E02i 3/00 [58] Field of Search ..'..2l4/l33, 138, 132,

Primary ExaminerGerald M. Forlenza Assistant Eia miner Ilohn Mannii Attorney-Max Dressler, James W. Clement et al.

[ 57] ABSTRACT The invention relates to an improved support means for a boom ram that swings a boom about a horizontal pivot axis on a support. The support means consists of a link pivoted on the support with the cylinder of the ram pivotally carried by the link. The support has first and second spaced stops located in the pivotal path of movement for the link. Releasable lock means are carried by the frame and cooperate with the link to maintain the link in engagement with either of the stops defining first and second positions for the link. In one position, the longitudinal axis of the boom is at all times located rearwardly of a vertical plane extending through the boom pivot, while in the second position, the longitudinal axis is located forwardly of the vertical plane when the ram is fully retracted to define a transport position for the boom.

11 Claims, 5 Drawing Figures Patented May 22, 1973 2 Sheets-Sheet 1 FIG. I

.' m mum Patented May 22, 1973 3,734,320

2 Sheets-Sheet 2 FIG.4

SUPPORT MEANS FOR BOOM RAM BACKGROUND OF THE INVENTION The present invention relates to an improvement in backhoes of the type disclosed in Long et al. US. Pat. No. 3,376,984.

Material handling machines, such as backhoes, include a boom carried by a support for pivotal movement in a substantially vertical plane about a horizontal axis- The pivotal movement of the boom about the horizontal pivot axis is usually accomplished by power means that normally consist of a cylinder and piston rod assembly interposed between the boom and the support. The hydraulic cylinder is generally connected for pivotal movement about a horizontal axis on the support, while the outer end of the piston rod is generally pivotally connected to the boom. The material handling unit is supported at the outermost end of the boom and in a backhoe, the unit consists ofa dipper stick assembly that includes a dipper stick pivoted intermediate its ends on the boom by a further fluid ram with a bucket pivoted on the free end of the dipper stick by a bucket fluid ram.

SUMMARY OF THE INVENTION According to the primary aspect of the present invention, the material handling implement includes a support for the boom ram that is capable of normally operating the boom along one side of the vertical plane, extending through the boom axis on the support, and capable of moving the position of the ram so that the boom can be located on the opposite side of the vertical plane by mere retraction of the ram.

In the illustrated embodiment, this is accomplished by supporting one end of one of the elements of the fluid ram on a link that is pivoted on the support between first and second positions. The first and second positions are defined by spaced stops forming part of the fixed support with positive remotely controlled means for locking the link in either of the two positions.

The locking means consists of a wedge having an inclined camming surfaces that cooperates with spaced camming surfaces on the link with the wedge being movable between extended and retracted positions by a small fluid ram. The locking arrangement allows for a positive locking force being applied to the link with a minimum amount of pressure on the fluid utilized with the ram.

It is also desirable to substantially reduce the load on the boom fluid ram while the vehicle is in the transport position. This is accomplished by forming a cradle on the support for receiving the boom in its transport position.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF DRAWINGS FIG. 1 shows a fragmentary elevation view of a vehicle having a backhoe supported on the rear end thereof;

FIG. 1a is a fragmentary view of the implement showing the boom in its transport position;

FIG. 2 is a plan view of the support for the boom and the fluid rarn;

FIG. 3 is an enlarged fragmentary side elevation view of the ram support; and

FIG. 4 is a view of the ram support and its locking means.

DETAILED DESCRIPTION FIG. 1 of the drawings discloses a vehicle 10 having a material handling unit or implement 12 supported thereon by a boom 14. In the illustrated embodiment, the implement is shown as a dipper stick assembly that includes a dipper stick 16 pivoted at 18 on the outer end of the boom by a fluid ram 20. A bucket 22 is piv oted on the opposite end of the dipper stick 16 through a further fluid ram 24 which may have linkage means 26 interposed between the bucket and the ram to compound the movement of the bucket in relation to movement of the ram.

The inner end of the boom 14 is pivoted about a horizontal pivot axis 30 defined on a support 32 that is normally referred to as the swing tower of the backhoe. The swing tower 32 is mounted for pivotal movement about a vertical axis on the vehicle by a pair of arms 34 and pins 36. Normally the swing tower 32 is pivoted about the vertical pivot axis defined by pins 36 through fluid rams (not shown) while the boom 14 is pivoted about the horizontal pin 30 through a ram assembly 40 that includes a cylinder 42 pivoted on the support or swing tower 32 with the free end of the piston rod 44 pivotally connected at 46 to the boom at a location spaced form a pivot pin 30.

As was indicated above, it is normally desirable to have the boom 14 pivotable between the raised and lowered positions on one side of a vertical plane extending through the pivot axis when the implement is being utilized for a digging operation. This is usually necessary in order to obtain the desired reach and depth with the bucket.

However, such an arrangement locates the center of gravity for the material handling unit substantially rearwardly of the tractor. When the entire unit is being transported from one site to another, it is desirable to locate the center of gravity for the unit as close as possible to the vehicle.

As is explained in more detail in the above mentioned Long et al. patent, the center of gravity is moved forwardly a substantial distance by having the boom extend generally vertically and slightly forwardly of the vertical plane extending through the pivot axis 30. In the previously mentioned patent, this is accomplished by proper manipulation of the boom cylinder to a fully retracted position and then partially extending the ram to pivot the boom forwardly of the vertical plane.

According to the present invention, the same condition for the boom in the transport position, as shown in the Long et al. patent, is accomplished by repositioning the pivot axis for the fluid ram so that the boom can be moved to the transport position by mere retraction of the boom ram elements to the fully retracted position. In the illustrated embodiment, the head end of the cylinder 42 is pivotally connected to one end of a link 50 by a pin 52. The link in turn, is pivotally supported intermediate its ends on the swing tower or support 32 by a second pin 54 (FIGS. 2 and 3). To maintain the link in a fixed position, relative to the axis for the pin 54, the pivotal support for the link 50 includes a collar 56 extending between spaced side plates 32a that form part of the swing tower or frame for the boom.

As is shown in FIG. 3, the link is pivoted between first and second positions which are respectively defined by stops 60 and 62. These stops are produced on a plate 64 that extends between the spaced side plates 32a and supports the swing tower on the arms 34. The surfaces 60 and 62 that define the respective stops on the frame are located substantially perpendicular to each other and are disposed in the pivotal path of movement of the link.

Thus, in one position (shown in solid line in FIG. 3) one portion of one edge of the link engages the stop 61) to define a first portion for the link while a second portion of the edge of the link engages the second surface or stop 62 to define the second position for the link (shown in dotted line in FIG. 3).

In the first position for the link, the boom 14 assumes a position substantially as shown in FIG. 1 when the ram 40 is fully retracted. It will be noted that the longitudinal axis of the boom is located on one side or rearwardly of a vertical plane extending through the axis defined by the pin 30 for the boom M. When the link is in the second position shown in FIG. 3 and the ram 40 is fully retracted, the boom assumes a position substantially as shown in FIG. la wherein the longitudinal axis for the boom is located on the other side or forwardly of the vertical plane extending through the pivot 30 for the boom.

It is also desirable to define a substantially fixed position for the boom in the transport position. For this purpose, a plate 70 extends between the side plates 32a of the frame and cooperates therewith to define a cradle for receiving and supporting the boom in the transport position, as shown in a dotted line of FIG. 3. Thus, the fluid trapped in the rod end of the cylinder 42., will hold the boom in a substantially fixed position against the plate 70.

While the link may be held either of two positions by suitable pins, it is desirable to be able to reposition the link without the operator leaving the operators station. Thus, according to another aspect of the invention, releasable lock means are carried by the frame and cooperate with the link to maintain the link in either of the two positions, respectively defined by the stops 60 and 62..

The releasable lock means is shown in FIG. 4 and consists of a wedge 72 having an inclined surface 74 that cooperates with appropriately spaced camming surfaces 76 and 78 defined on the link 50. The wedge 72 with its inclined camming surface 74 is moved between locked and released or extended and retracted positions on the frame by drive means that consists of a fluid ram 80 having its piston rod $2 connected to the wedge and its cylinder 84 supported on the frame by a plate 86 (FIG. 2) secured to one of the side plates 32a.

The frame 32 further has guide means for guiding the wedge between extended and retracted positions. As shown in FIG. 3, the guide means consists of first and second perpendicularly positioned plates 88 and 90 that respectively cooperate with perpendicular surfaces on the wedge to define the guide on the frame.

When it is desired to move the link from one position to the other, the boom is lowered to a position where the bucket is supported on the ground. Fluid under pressure is then delivered to the port 92 on the cylinder 84 to retract the wedge. Thereafter, the boom ram may be actuated to move the link 50 from the solid to the dotted line position of FIG. 3. After the link has been moved to the second position and is in engagement with the stop 62, fluid under pressure is delivered to the port 94 on the head end of cylinder 84 to force the wedge 72 between the plate and the inclined camming surface 78.

It will be seen that because of the relationship of the various parts no close tolerances need to be maintained with respect to either of the camming surfaces on the link or the camming surface on the wedge and the link need only be within general dimensions. This is of considerable advantage in reducing the cost of manufacturing a device of this type.

When the cylinder 84 has been shown as a doubleacting cylinder, it is readily apparent that a single acting cylinder in either direction may be substituted.

The two positions for the pivot 52 for the ram are intended primarily for locating the ram so that the boom can be moved to the transport position by retraction of the ram. However, it will be apparent that the movement of the link between the two positions also changes the moment arm for the ram pivoting the boom.

It will be noted that the boom or first pivot 30 is located adjacent the bottom end of the swing tower while the link or second pivot 54 is located adjacent the upper end of the swing tower. Thus, by moving the link from a solid to the dotted line position of FIG. 3, the moment arm for the fluid ram 40 is increased to allow for providing additional force to the boom in either the raising or the lowering process.

It should also be noted that FIG. 2 shows a means for locking the swing tower in a fixed position relative to the main frame or the arms 34. As shown in FIG. 2, the plate 64 has an ear 96 that extends forwardly in overlapping relation with respect to the dipper arm 34 and the ear 96 and arm 34 have openings 98 that are aligned with each other when the boom extends directly rearwardly of the tractor. A pin can be inserted through the aligned openings 98 to lock the swing tower and the boom in a position where it extends rearwardly along the longitudinal center for a tractor. This is desirable so that the weight of the material handling unit is located along a longitudinal axis for the vehicle.

I claim:

I. In a backhoe having a frame and an elongated boom supported at one end about a first pivot on said frame by a fluid ram having relatively movable elements, a ram support comprising a link supported intermediate its ends about a second pivot on said frame, first and second spaced stops on said frame and located in the path of pivotal movement of said link; and releasable lock means carried by said frame and cooperating with said link to maintain said link in either of two positions defining by said stops, said releasable lock means including a member for engaging said link and means for moving said member between engaged and released positions relative to said link.

2. A backhoe as defined in claim l, in which said member has an inclined camming surface and said link has first and second cooperating surfaces located at substantially right angles to each other, said inclined camming surface engaging one of said cooperating surfaces in the respective positions for said link.

3. A backhoe as defined in claim I, in which said means for moving includes a cylinder connected to said frame and a piston rod reciprocated in said cylinder and connected to said member.

4. A backhoe as defined in claim I, in which said elongated boom has a longitudinal axis and in which a major portion of said axis is located on one side of said pivot as said elements are extended and retracted when said link is located in one of said positions and the major portion of said axis is moved to the opposite side of said axis when said link is in the other of said positions and said elements are fully retracted.

5. A backhoe including a frame having first and second vertically spaced pivot means; a boom pivoted at one end on said first pivot means; a link pivoted on said second pivot means; a fluid ram having first and second elements relatively movable between extended and retracted positions with one of said elements pivoted to said link at a location spaced from said second pivot means and the other of said elements pivoted to said boom at a location spaced from said first pivot means, said link having a first position locating said boom on one side of a vertical plane extending through said first pivot means, said link being movable from said first position to a second position, said second position for said link accommodating movement of said boom to the opposite side of said vertical plane upon complete retraction of said elements to define a transport position for said boom.

6. A backhoe as defined in claim 5, further including means defining a cradle on said frame for receiving and supporting said boom in the transport position.

7. A backhoe as defined in claim 5, in which said frame has first and second stops located in the path of said link and defining said first and second positions for said link; further including lock means for maintaining said link against said stops in the respective positions for said link.

8. A backhoe as defined in claim 7, in which said lock means includes a member having an inclined camming surface and means for moving said member between retracted and extended positions on said frame, said link having first and second angularly related surfaces respectively engaged by said camming surface in the respective positions for said link.

9. In a backhoe having a frame and a boom pivoted at one end on the lower portion of said frame by a fluid ram, a ram support comprising a link pivoted between extreme positions on the upper portion of said frame with said ram pivoted on said link at a location spaced from the pivot for said link; and lock means cooperating with said link for maintaining said link in either of said extreme positions, said lock means including a wedge operating with said link and drive means between said frame and said wedge for moving said wedge between locked and released positions.

10. A backhoe as defined in claim 9, in which said wedge has an inclined camming surface and said link has a pair of cooperating surfaces angularly related to each other and respectively engaged by said camming surface in the extreme positions for said link.

11. A backhoe as defined in claim 10, further including guide means on said frame for said wedge, and in which said drive means includes a cylinder and piston rod assembly between said wedge and frame to move said wedge between locked and released positions on said frame. 

1. In a backhoe having a frame and an elongated boom supported at one end about a first pivot on said frame by a fluid ram having relatively movable elements, a ram support comprising a link supported intermediate its ends about a second pivot on said frame, first and second spaced stops on said frame and located in the path of pivotal movement of said link; and releasable lock means carried by said frame and cooperating with said link to maintain said link in either of two positions defining by said stops, said releasable lock means including a member for engaging said link and means for moving said member between engaged and released positions relative to said link.
 2. A backhoe as defined in claim 1, in which said member has an inclined camming surface and said link has first and second cooperating surfaces located at substantially right angles to each other, said inclined camming surface engaging one of said cooperating surfaces in the respective positions for said link.
 3. A backhoe as defined in claim 1, in which said means for moving includes a cylinder connected to said frame and a piston rod reciprocated in said cylinder and connected to said member.
 4. A backhoe as defined in claim 1, in which said elongated boom has a longitudinal axis and in which a major portion of said axis is located on one side of said pivot as said elements are extended and retracted when said link is located in one of said positions and the major portion of said axis is moved to the opposite side of said axis when said link is in the other of said positions and said elements are fully retracted.
 5. A backhoe including a frame having first and second vertically spaced pivot means; a boom pivoted at one end on said first pivot means; a link pivoted on said second pivot means; a fluid ram having first and second elements relatively movable between extended and retracted positions with one of said elements pivoted to said link at a location spaced from said second pivot means and the other of said elements pivoted to said boom at a location spaced from said first pivot means, said link having a first position locating said boom on one side of a vertical plane extending through said first pivot means, said link being movable from said first position to a second position, said second position for said link accommodating movement of said boom to the opposite side of said vertical plane upon complete retraction of said elements to define a transport position for said boom.
 6. A backhoe as defined in claim 5, further including means defining a cradle on said frame for receiving and supporting said boom in the transport position.
 7. A backhoe as defined in claim 5, in which said frame has first and second stops located in the path of said linK and defining said first and second positions for said link; further including lock means for maintaining said link against said stops in the respective positions for said link.
 8. A backhoe as defined in claim 7, in which said lock means includes a member having an inclined camming surface and means for moving said member between retracted and extended positions on said frame, said link having first and second angularly related surfaces respectively engaged by said camming surface in the respective positions for said link.
 9. In a backhoe having a frame and a boom pivoted at one end on the lower portion of said frame by a fluid ram, a ram support comprising a link pivoted between extreme positions on the upper portion of said frame with said ram pivoted on said link at a location spaced from the pivot for said link; and lock means cooperating with said link for maintaining said link in either of said extreme positions, said lock means including a wedge operating with said link and drive means between said frame and said wedge for moving said wedge between locked and released positions.
 10. A backhoe as defined in claim 9, in which said wedge has an inclined camming surface and said link has a pair of cooperating surfaces angularly related to each other and respectively engaged by said camming surface in the extreme positions for said link.
 11. A backhoe as defined in claim 10, further including guide means on said frame for said wedge, and in which said drive means includes a cylinder and piston rod assembly between said wedge and frame to move said wedge between locked and released positions on said frame. 